generate unique strings of characters

[needs_upgrade]

Hello guys. 

 

How can i make 50,000 unique string characters? What i have in mind is to md5() numbers 1-50,000. But my client wants those strings to be 10 characters in length only. Where should i start? Thanks guys!

[Jessica]

The numbers 1 through 10,000 are already unique

[Jessica]

Er, 50,000.

[jugesh]

Here I am sharing my code which I have written to generate unique nos. Please go through it hope It will help u out.

      function uniqueID($table){
// The length we want the unique reference number to be
$unique_ref_length = 10;
// A true/false variable that lets us know if we've
// found a unique reference number or not
$unique_ref_found = false;
// Define possible characters.
// Notice how characters that may be confused such
// as the letter 'O' and the number zero don't exist
 $possible_chars = "23456789abcdefghijklmanopqrstuvwxyz";
// Until we find a unique reference, keep generating new ones
while (!$unique_ref_found) {
            // Start with a blank reference number
    $unique_ref = "";
    // Set up a counter to keep track of how many characters have
    // currently been added
    $i = 0;
    // Add random characters from $possible_chars to $unique_ref
    // until $unique_ref_length is reached
    while ($i < $unique_ref_length) {
        // Pick a random character from the $possible_chars list
        $char = substr($possible_chars, mt_rand(0, strlen($possible_chars)-1), 1);
        $unique_ref .= $char;
        $i++;
    }
        $unique_ref = $unique_ref;
    // Our new unique reference number is generated.
    // Lets check if it exists or not
    $query = "SELECT `CommonID` FROM ".$table." WHERE `CommonID`='".$unique_ref."'";
    $result = mysql_query($query) or die(mysql_error().' '.$query);
    if (mysql_num_rows($result)==0) {
        // We've found a unique number. Lets set the $unique_ref_found
        // variable to true and exit the while loop
        $unique_ref_found = true;
    }
}
return $unique_ref;
}

[annaharris]

Try this code:
 

<?php

$i = 1;
while ($i <= 50000) {
echo(rand(1000000000,9999999999));
$i++; /* the printed value would be
$i before the increment
(post-increment) */
}